Select multiple nodes/edges

[keyserj]

Is your feature request related to a problem? Please describe. Sometimes it'd be nice to interact with multiple nodes or edges at the same time - for mass-deleting, or even just having multiple parts highlighted (after #196 , this will probably be significantly more desired, for mass-moving).

Describe the solution you'd like Allow me to select multiple nodes and edges, potentially through:

• ctrl + click to add another part to the selection
• click + drag to select many parts at once (currently left-click pans; perhaps we can use ctrl + left-click for select?)

Multi-select actions:

• mass-delete
• mass-connect to another node
• copy/paste to another diagram (probably future)

Draw.io and miro.com will be good references for how this functionality can work, e.g. Draw.io looks like this for the above two things:

Describe alternatives you've considered

Additional context Discord convo https://discord.com/channels/1057707973482401892/1057707973482401899/1148994000909516870

Technical ideas

• react flow probably has built-in multi-select functionality
• we're probably hardcoding some assumptions that only one part is selected at a time